1. Field of the Invention
The present invention relates to an impact printer, and more particularly to print pressure control for a printer which impacts a type to a paper with an ink ribbon being interposed between a type wheel and the paper.
Still more particularly, it relates to a print pressure control device which adjusts a print pressure depending on a type of the type wheel to attain a high quality of print.
2. Description of the Prior Art
A 10-pitch type wheel for printing ten characters per inch and a 12-pitch type wheel for printing twelve characters per inch are usually available. The 10-pitch type wheel has a relatively large type surface area while the 12-pitch type wheel has a relatively small type surface area. A printer has a print pressure setting switch so that an operator can selectively set a print pressure, apart from the type wheel. If the operator wants a high print pressure, he or she may set the switch to a high position, and if he or she wants an ordinary print pressure, he or she may set the switch to an ordinary position.
However, if the print pressure is set to high when the 12-pitch type wheel is loaded, the high print pressure is applied in spite of the small type surface area and the paper is embossed. As a result, a high quality of print is not attained.